84 The Microscope. 



cially since they may be made for next to nothing. The reader 

 will find that it will add a good deal of pleasure to micro- 

 scopical work to make one's own tools, as nearly all that the 

 microscopist needs may be so made. Glass slips and covers 

 and a few chemicals he is forced to buy ; all else he has within 

 himself, if he is the least ingenious. And indeed, he need not 

 be ingenious, if that term should mean of an inventive turn of 

 mind, for the books give explicit directions for the making of 

 the few tools that the woi'ker will need. At least that is one 

 of the objects of this little manual. The making of glass rings 

 will be referred to again with directions as to the method. 



Deep cells are used so that with large or thick objects the 

 cover glass ma}' not be forced to lie upon the specimen. If the 

 object were compelled to bear the weight of the cover it might 

 be crushed or injured, and the thin cover itself would be in 

 danger of breakage. The breaking is easily done at any time, 

 but to have the glass resting unevenly on the object would be to 

 invite disaster. The difficult}^ also of cementing the cover in 

 place over a thick object is greatl}^ increased. A thick ring is 

 therefore cemented fast to the slip, the object and the mounting 

 medium placed within it, and the cover put on the ring and 

 cemented down. 



METAL RINGS. 



The dealers have for sale fine rings of block tin of various 

 thicknesses and diameters. These are excellent; they make a 

 pleasing mount, and the microscopist will need some of various 

 sizes, if he is to do much work with large and thick objects. No 

 mounting medium should be used with them that will have smy 

 chemical action on the tin, or the preparation will soon be 

 spoiled. The}' should be selected for the largest and thickest 

 objects only. For thinner specimens there is another kind to 

 be had nearer home. 



These are curtain rings of brass, to be had in variou? sizes 

 from any hardware store. Select the size needed and with a 

 hammer pound them flat on a smooth, hard surface, like that of 

 a sad-iron, for instance. It needs a little skill to do this without 

 distorting and so ruining the ring, but sight practice will teach 

 it. These, for comparatively thin objects, are as good as the tin 

 rings. The only possible objection to them is that if they are 

 not so flattened that the surfaces are in contact, when they come 



